Field vapor extraction test and long-term monitoring at a PCE contaminated site.

The results of a field investigation, vapor extraction tests, and long-term monitoring at a PCE-contaminated site in Saga, Japan, are reported. The field investigation indicated that PCE likely was trapped in a surface clayey sand layer (vadose zone), and soil vapor extraction (SVE) was adopted as the remediation approach. The field test results the effectiveness of SVE in removing volatile organic compounds (VOCs) from contaminated sites. For the case where the radius of influence for an extraction well was 15-20 m, the blower capacity had no obvious effect on the radius of influence possibly due to the short circuiting of air from the ground surface. However, the maximum negative pressure (difference between vapor pressure and ambient pressure) in the extraction well was approximately proportional to blower capacity for the range of blower capacities tested. The long-term monitoring results indicate that PCE concentration varied seasonably, and temperature and rainfall are two of the influencing factors.